Thanks for your great post… But I’m seeking and still can’t see how to put captcha before publish post, I have seen this some sites but can’t find the plugin. All of them almost the same to prevent auto comment, registration.
As you stated that you want a captcha before a post, i think you are using wordpress. There is a plugin available for reCaptcha the famous captcha service. Otherwise you can go to the same site and look for a no of php examples which will teach you the Captcha integration. Do tell if more help is needed.
As in the above post you stated that you can not find the plugin, so if again i guess you are using wordpress . the plugin can be found here